1. Field of the Invention
The present invention relates to small internal combustion engines of the type typically used with lawnmowers, lawn and garden tractors, small sport vehicles, or other small working implements. In particular, the present invention relates to the positioning and operation of the engine controls and other user interface components of such engines.
2. Description of the Related Art
Small internal combustion engines are typically configured as horizontal crankshaft engines or vertical crankshaft engines. Horizontal crankshaft engines are often used in applications such as snow throwers and generators, for example, while vertical crankshaft engines are often used in applications such as walk-behind lawnmowers and lawn and garden tractors, for example, although the foregoing usage may vary. Horizontal and vertical crankshaft engines typically include one or two engine cylinders, and have drive trains configured as L-head/side valve type, overhead valve (“OHV”) type, and overhead cam (“OHC”) type.
Additionally, small internal combustion engines typically include a number of user interfaces which are manipulated by a user of the engine in order to operate, maintain, and service the engine. These user interfaces include engine controls for starting, stopping, and varying the speed of the engine. For example, in engines with carburetors, a choke control is actuated to provide an enriched air/fuel mixture to the engine to aid in starting, and a throttle control is used to regulate the amount of air/fuel mixture delivered to the engine in order to vary the engine speed. Other engine controls include ignition switches for enabling or disabling engine ignition, as well as fuel shut-off valves for opening and closing the flow of fuel from the fuel tank of the engine to the carburetor.
In addition to the engine controls, other user interfaces for small internal combustion engines include the fuel tank cap, which is removed from the fuel tank for filling fuel into the fuel tank, as well as the oil fill cap, which is removed from the oil fill conduit for filling oil into the crankcase of the engine.
The foregoing user interfaces must be accessed by a user, some more frequently than others, for operating, maintaining, and servicing the engine. However, a problem with known small engines is that these interfaces are typically distributed at various locations around the engine housing. As an example, a single cylinder horizontal shaft engine may include a fuel tank at the top and to one side of the engine, the fuel tank including the fuel tank cap; an oil fill conduit at a lower rear portion of the engine, the oil fill conduit including the oil fill cap; carburetor throttle and choke controls at a lower left portion of the engine on the front side; and a carburetor primer bulb on an upper front side of the engine, etc. Further, positioning of the user interfaces is often not consistent from engine to engine.
Problematically, positioning of the user interfaces at various locations around the engine often makes at least some of the user interfaces inconvenient for ready access by the user, and in some cases, may make it difficult for the user to locate and/or identify particular user interfaces when same need to be accessed.
Further, the carburetor throttle and choke controls for small engines are typically in the form of slide levers which tend to occupy a large amount of space at the engine surface, which space is often at a premium in small engines. The carburetor and choke controls may be located on the engine in a manner in which they are not easily and readily accessible by the user.
What is needed is a small internal combustion engine having user interfaces which are positioned and operable in a manner which is an improvement over the foregoing.